1. Field of the Invention
The present invention relates to new piperidino-pentanamines, both individually and as a mixture, namely 2-methyl-5-(3-methylpiperidino)pentanamine and the isomeric 4-methyl-5-(3-methylpiperidino)pentanamine, which can be represented by the common formula ##STR2## In this formula, in both cases, one of the two radicals R.sup.1 and R.sup.2 is hydrogen and the other is methyl. In the case of 2-methyl-5-(3-methylpiperidino)pentanamine (Ia), R.sup.1 =methyl and R.sup.2 =H, in the case of 4-methyl-5-(3-methylpiperidino)pentanamine (Ib), R.sup.1 =H and R.sup.1 =methyl. Each of the two compounds can exist in four different stereoisomeric forms (two diastereomeric pairs). Here and in the following, the formulae and the associated names of compounds represent all possible stereoisomers in each case.
The invention further relates to a process for preparing the abovementioned compounds from 2-methylglutaronitrile and the use of the compounds as catalysts for producing polyurethanes from polyisocyanates and polyols.
2. Background Art
Polyurethanes are customarily produced using nitrogen bases, in particular tertiary amines such as 1,4-diazabicyclo[2.2.2]octane (DABCO.RTM.), cyclic amidines such as 1,8-diazabicyclo[5.4.0]undec-7-ene ("DBU") or guanidine derivatives such as tetramethylguanidine as catalysts. Decisive for the suitability as catalyst are, inter alia, the basicity, solubility behavior and volatility. While the basicity primarily determines the catalytic effectiveness, solubility behavior and volatility are likewise important for the processing properties. For example, volatility which is too high can lead to irritation or danger to people as a result of liberation into the atmosphere during the production of the polyurethanes or during their use.